Description: (Applicant's Description) The purpose of the Confocal Microscopy Core is to enhance the peer-reviewed funded research activities of CCC members whose research requires confocal microscopy and related techniques. Capabilities and services include: High resolution conventional light microscopy, in situ hybridization, cytochemistry, histochemistry, immunocytochemistry, immunohistochemistry, intracellular trafficking studies, multiple labeling studies (up to 3 different parameters can be studied at the same time) and ratioing (e.g., intracellular pH and ion measurement studies), as well as three dimensional image reconstruction and quantitative measurements. The confocal imaging system consists of a Zeiss LSM 310 confocal microscope equipped with three lasers and its SiliconGraphics workstation, a Meridian ACAS 570 Analytical Cytometer equipped with one laser (tunable to three wavelengths) and a separate work station, and a Meridian InsightPlus confocal microscope also equipped with one laser. The facility also provides conventional fluorescent microscopy through a Zeiss Axiophote Dual-Camera Photomicroscope. In addition to the SiliconGraphics and the Meridian workstations, the analytical systems of the Confocal Microscopy Core include two Macintosh G3 computers with several photographic quality printers as well as various types of analytical software.